Microbes that live inside the human body provide a wide range of functions that the human body lacks. However, they are also linked to diseases, such as Crohn's disease and ulcerative colitis (collectively called inflammatory bowel disease, or IBD). Recently, it has been shown that newborns carry bacteria transferred from their mothers. We would like to determine how and when maternal bacteria are transferred to a baby from mothers with and without IBD. This information can help us develop novel strategies to limit risk transmission from a mother to a baby.